Dual Band Quads

21Mhz OWA Yagi Antennas

A 14el 28 Ohm 144MHz Optimised Wideband Low impedance (OWL) Yagi

Revised  August 2014

Premium commercial versions of this antenna at Innovantennas

The OWL by G0KSC provides the benefits of both OWA (Optimised wideband Array) 50 Ohm antennas with those of traditional low impedance antennas. More information on the OWL can be found here

Visit HERE to learn how to make the OWL Match/Balun

Do not look at the gain figure of this antenna and compare with other 14 element 144MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 16.74dBi (10mm element version) and a boom less than 9M long, this antenna will be a winner for field days and the rural Ham radio operator. Class leading G/T figures too!

 

PLEASE NOTE:

  • Visit 'Making the OWL Match' for more information on the recommended matching methods
  • Please add 2mm to each element to allow for insulator correction if using insulators similar to G0KSC. If through boom/insulator/element bolts are used, add 3mm

 

 

Performance UK/USA Version

Forward Gain:                           16.74dBi at 144.300MHz

Front to Back Ratio:                 28.94dBi at 144.300MHz

Peak Gain:                                 16.76dBi

Peak F/B:                                  28.95dB

Bandwidth:                               1.3MHz below 1.1:1

 

Build Dimensions for UK/USA Version

Element      Spacing in metres Half element Length in metres    Element Notes

Reflector               0                                   .5135                          3/8 inch tube

DE                       .229                               .490                           1/2 inch tube

D1                       .390                               .4765                          3/8 inch tube

D2                       .770                               .4675                          3/8 inch tube

D3                     1.365                               .4585                          3/8 inch tube

D4                     2.087                               .4495                          3/8 inch tube

D5                     2.876                               .4435                          3/8 inch tube

D6                     3.714                               .438                            3/8 inch tube

D7                     4.586                               .4335                          3/8 inch tube

D8                     5.471                               .4295                          3/8 inch tube

D9                     6.372                               .4245                          3/8 inch tube

D10                   7.302                               .4175                          3/8 inch tube

D11                   8.292                               .4155                          3/8 inch tube

D12                   8.996                               .4385                          3/8 inch tube

 

Build Dimensions for European Version

Element     Spacing in metres Half element Length in metres    Element Notes

 

Reflector               0                                   .513                         10mm tube

DE                       .229                               .491                         12mm tube

D1                       .390                               .476                         10mm tube

D2                       .770                               .467                         10mm tube

D3                     1.365                               .458                         10mm tube

D4                     2.087                               .449                         10mm tube

D5                     2.876                               .443                         10mm tube

D6                     3.714                               .4375                       10mm tube

D7                     4.586                               .433                         10mm tube

D8                     5.471                               .429                         10mm tube

D9                     6.372                               .424                         10mm tube

D10                   7.302                               .417                         10mm tube

D11                   8.292                               .415                         10mm tube

D12                   8.996                               .438                         10mm tube

 

Antenna Plots

 

Fantastic Azimuth plot of this 14el 144MHz OWL Yagi

 

 

The Elevation plot is really clean too. A quiet antenna compared with most!

 

 

This SWR plot is taken with the Coaxial stub embedded within the EZNEC model Ever seen a 28 Ohm antenna like this one before? Watch how many now appear on the Internet but remember where you saw them first!

 

The G0KSC OWL element layout. Note the close spacing of the first 3 elements which give the OWL its extra gain and wide bandwidth.

 

As always, or if you have difficulty at all, please Email me!

 

Justin G0KSC